The Kew Gardens (Leases) (No. 3) Bill [HL] is a government bill that would extend the maximum allowable lease on Kew Gardens’ land from the current 31 to 150 years. On 25 April 2019, Lord Gardiner of Kimble, the Parliamentary Under Secretary of State for Rural Affairs and Biosecurity, introduced the bill in the House of Lords. It is due to have its second reading on 7 May 2019. The bill is almost identical to two private member’s bills currently before Parliament. The first was introduced in the House of Lords by Lord True (Conservative) in July 2017, with the second being introduced in the House of Commons by Zac Goldsmith (Conservative MP for Richmond Park) in January 2018. Neither bill has yet received a second reading.

The Government has stated that the purpose of extending the lease is to enable the Royal Botanic Gardens (RBG), Kew to open new streams of revenue, enabling it to become more self-sufficient in funding. Currently, the freeholds for the land and buildings used by RBG Kew have different ownership, with the land and building at Kew owned by the Crown. It is funded through a combination of grant-in-aid from the Department for Environment, Food and Rural Affairs (DEFRA), self-generated income and charitable donations.

The purpose of RBG Kew has changed over time, from a philanthropic enterprise in the 18th and 19th centuries to botanical gardens and Kew Science today. In this time, the management has also changed, with the National Heritage Act 1983 creating a board of trustees. RBG Kew achieved UNESCO World Heritage Site status in 2003.